Conveyors have become the backbone of most industrial operations, moving parts and materials from one work station to another. A common form of the conveyor is based upon a wide belt carried by rollers, or by a skid plate, depending upon the load that is carried. Strictly linear movement is only a minor design problem, but turning a flat belt in the plane of its width is another matter. The belt buckles along the inner periphery of the turn, if the same belt used for the linear movement is deflected around any substantial deviation from a straight line. The solution to the problem has been a separate unit forming a turn in the conveyor path. Carried objects are transferred from the linear section to the corner at their end points, so that the corner section forms a continuation of the linear system.
The corner conveyor is based on arcuate sections of belt joined at their ends to form a continuous band, and is carried by a frame with rollers positioned to establish upper and lower courses, one overlying the other. This endless belt is typically driven either at the end rollers, or by deviating the lower course of the belt around drive rollers at an intermediate location around the turn. The belt is thus forced into a serpentine path that aggravates wear and installation problems, as well as requiring considerable structure associated specifically with the drive.
The placement of the belt has been improved by receiving the outer edge in a slot in a tubular guide rail. The belt can then be provided with a plurality of rollers spaced along a line somewhat inward from the outer edge (with respect to the radius of the turn), so that these rollers can bear on the radially outer surface of the slotted face of the rail (which would be the inside of the tubular configuration). This interengagement maintains the arcuate path, which might otherwise be distorted by belt tension.